1. Field of the Invention
The present invention relates to a motor, and more a direct drive torque motor which is used for various angle controlling, rotation speed controlling and precision controlling, thus the product can be improved in life and is adapted for modular application.
2. Description of the Prior Art
The motors are used more and more widely in modern industries, and are generally categorized into external rotor, internal rotor and so on. In addition to the high precision in the feeding transmission, the motor also has the advantages of low friction loss, high energy conversion efficiency and low noise, etc. Hence, the motor is obviously important to the modern industrial tool machines.
The existing direct drive motors are applied to the drive of the axis equipments, such as the automatic equipment, the indexing plate and each kind of tool machine. With reference to FIGS. 1 and 2, a clearance eliminating structure for the main shaft of a conventional direct drive torque motor utilizes the coil 101 of an outer stator 10 to closely cooperate with the magnet 111 of the inner rotor 11. A shaft 12 is fixed in the center of the inner rotor 11. The outer stator 10 includes an annular base 102, an annular aluminum sheet 103, a silicon steel sheet 104 and the coil 101 that are arranged sequentially from the outer to the inner periphery of the outer stator 10. Thought it has been brought into use, this design still has the following disadvantages:
First, this conventional direct drive torque motor can drive the fixed shaft 12 of the inner rotor 11, but it still has to use the coil 101 of the outer stator 10 to cooperate with the magnets 111 of the inner rotor 11 to carry out the operation control of starting or stopping the rotation. However, this simple operation control doesn't have a precision rotating and stopping control mechanism for precisely controlling and stopping the rotation, so it is unsuitable for use in various precision controls (such as circular motion control and angle decomposition).
Second, since the conventional direct drive torque motor is not provided with a position sensing assembly, through the direct drive motor can drive the fixed shaft 12 of the inner rotor 11 to rotate, the rotation angle and the number of revolutions of the shaft 12 is unavailable. Further, there is no appropriate method existing to install the aforementioned assemblies on the conventional direct drive torque motor.
Third, this conventional direct drive torque motor must be mounted on a machine to carry out rotating operation and is not adapted for modular application since its heavy body is undetachable. Further, the market is awaiting new products which can be easily and independently used for various angle controlling, rotation speed controlling and precision controlling.
Fourth, if the conventional direct drive torque motor is mounted on a machine to carry out rotating operation, there are no appropriate assemblies that can be used to support the inner rotor and the shaft, it is likely to cause abrasion to the components and considerably affect the life of the product.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.